canonpath
on Win32 now collapses foo/..
(or foo\..
) sections
correctly, rather than doing the "misguided" work it was previously doing.
Note that canonpath
on Unix still does not collapse these sections, as
doing so would be incorrect.

Some documentation improvements

Some internal code cleanup

FileCache
upgraded to version 1.06

POD formatting errors in the documentation fixed

Filter::Simple
upgraded to version 0.82

FindBin
upgraded to version 1.47

Now works better with directories where access rights are more
restrictive than usual.

GDBM_File
upgraded to version 1.08

Internal cleanup

Getopt::Long
upgraded to version 2.35

prefix_pattern
has now been complemented by a new configuration
option long_prefix_pattern
that allows the user to specify what
prefix patterns should have long option style semantics applied.

Options can now take multiple values at once (experimental)

Various bug fixes

if
upgraded to version 0.05

Give more meaningful error messages from if
when invoked with a
condition in list context.

Restore backwards compatibility with earlier versions of perl

IO
upgraded to version 1.22

Enhanced documentation

Internal cleanup

IPC::Open2
upgraded to version 1.02

Enhanced documentation

IPC::Open3
upgraded to version 1.02

Enhanced documentation

List::Util
upgraded to version 1.18 (was 1.14)

Fix pure-perl version of refaddr
to avoid blessing an un-blessed reference

Use XSLoader
for faster loading

Fixed various memory leaks

Internal cleanup and portability fixes

Math::Complex
upgraded to version 1.35

atan2(0,i)
now works, as do all the (computable) complex argument cases

Fixes for certain bugs in make
and emake

Support returning the kth root directly

Support [2,-3pi/8] in emake

Support inf
for make
/emake

Document make
/emake
more visibly

Math::Trig
upgraded to version 1.03

Add more great circle routines: great_circle_waypoint
and
great_circle_destination

Utility Changes

h2xs
enhancements

h2xs
implements new option --use-xsloader
to force use of
XSLoader
even in backwards compatible modules.

The handling of authors' names that had apostrophes has been fixed.

Any enums with negative values are now skipped.

perlivp
enhancements

perlivp
implements new option -a
and will not check for *.ph
files by default any more. Use the -a
option to run all tests.

New Documentation

The perlglossary manpage is a glossary of terms used in the Perl
documentation, technical and otherwise, kindly provided by O'Reilly Media,
inc.

Performance Enhancements

Weak reference creation is now O(1) rather than O(n), courtesy of
Nicholas Clark. Weak reference deletion remains O(n), but if deletion only
happens at program exit, it may be skipped completely.

Salvador Fandiño provided improvements to reduce the memory usage of sort
and to speed up some cases.

Jarkko Hietaniemi and Andy Lester worked to mark as much data as possible in
the C source files as static
, to increase the proportion of the executable
file that the operating system can share between process, and thus reduce
real memory usage on multi-user systems.

Installation and Configuration Improvements

Parallel makes should work properly now, although there may still be problems
if maketest
is instructed to run in parallel.

Building with Borland's compilers on Win32 should work more smoothly. In
particular Steve Hay has worked to side step many warnings emitted by their
compilers and at least one C compiler internal error.

Configure
will now detect clearenv
and unsetenv
, thanks to a patch
from Alan Burlison. It will also probe for futimes
and whether sprintf
correctly returns the length of the formatted string, which will both be used
in perl 5.8.9.

Perl extensions on Windows now can be statically built into the Perl DLL,
thanks to a work by Vadim Konovalov. (This improvement was actually in 5.8.7,
but was accidentally omitted from perl587delta).

Selected Bug Fixes

no warnings 'category' works correctly with -w

Previously when running with warnings enabled globally via -w
, selective
disabling of specific warning categories would actually turn off all warnings.
This is now fixed; now nowarnings'io';
will only turn off warnings in the
io
class. Previously it would erroneously turn off all warnings.

This bug fix may cause some programs to start correctly issuing warnings.

Remove over-optimisation

Perl 5.8.4 introduced a change so that assignments of undef to a
scalar, or of an empty list to an array or a hash, were optimised away. As
this could cause problems when goto jumps were involved, this change
has been backed out.

sprintf() fixes

Using the sprintf() function with some formats could lead to a buffer
overflow in some specific cases. This has been fixed, along with several
other bugs, notably in bounds checking.

In related fixes, it was possible for badly written code that did not follow
the documentation of Sys::Syslog
to have formatting vulnerabilities.
Sys::Syslog
has been changed to protect people from poor quality third
party code.

Debugger and Unicode slowdown

It had been reported that running under perl's debugger when processing
Unicode data could cause unexpectedly large slowdowns. The most likely cause
of this was identified and fixed by Nicholas Clark.

Smaller fixes

FindBin
now works better with directories where access rights are more
restrictive than usual.

Several memory leaks in ithreads were closed. An improved implementation of
threads::shared
is available on CPAN - this will be merged into 5.8.9 if
it proves stable.

Trailing spaces are now trimmed from $!
and $^E
.

Operations that require perl to read a process' list of groups, such as reads
of $(
and $)
, now dynamically allocate memory rather than using a
fixed sized array. The fixed size array could cause C stack exhaustion on
systems configured to use large numbers of groups.

PerlIO::scalar
now works better with non-default $/
settings.

You can now use the x
operator to repeat a qw// list. This used
to raise a syntax error.

The debugger now traces correctly execution in eval("")uated code that
contains #line directives.

The value of the open pragma is no longer ignored for three-argument
opens.

The optimisation of for (reverse@a)
introduced in perl 5.8.6 could
misbehave when the array had undefined elements and was used in LVALUE
context. Dave Mitchell provided a fix.

Some case insensitive matches between UTF-8 encoded data and 8 bit regexps,
and vice versa, could give malformed character warnings. These have been
fixed by Dave Mitchell and Yves Orton.

lcfirst and ucfirst could corrupt the string for certain cases where
the length UTF-8 encoding of the string in lower case, upper case or title
case differed. This was fixed by Nicholas Clark.

Perl will now use the C library calls unsetenv
and clearenv
if present
to delete keys from %ENV
and delete %ENV
entirely, thanks to a patch
from Alan Burlison.

This syntax error indicates that the lexer couldn't find the final
delimiter of a ?PATTERN?
construct. Mentioning the ternary operator in
this error message makes it easier to diagnose syntax errors.

Changed Internals

There has been a fair amount of refactoring of the C
source code, partly to
make it tidier and more maintainable. The resulting object code and the
perl
binary may well be smaller than 5.8.7, in particular due to a change
contributed by Dave Mitchell which reworked the warnings code to be
significantly smaller. Apart from being smaller and possibly faster, there
should be no user-detectable changes.

Andy Lester supplied many improvements to determine which function
parameters and local variables could actually be declared const
to the C
compiler. Steve Peters provided new *_set
macros and reworked the core to
use these rather than assigning to macros in LVALUE context.

Dave Mitchell improved the lexer debugging output under -DT

Nicholas Clark changed the string buffer allocation so that it is now rounded
up to the next multiple of 4 (or 8 on platforms with 64 bit pointers). This
should reduce the number of calls to realloc
without actually using any
extra memory.

The HV
's array of HE*
s is now allocated at the correct (minimal) size,
thanks to another change by Nicholas Clark. Compile with
-DPERL_USE_LARGE_HV_ALLOC
to use the old, sloppier, default.

For XS or embedding debugging purposes, if perl is compiled with
-DDEBUG_LEAKING_SCALARS_FORK_DUMP
in addition to
-DDEBUG_LEAKING_SCALARS
then a child process is forked just before
global destruction, which is used to display the values of any scalars
found to have leaked at the end of global destruction. Without this, the
scalars have already been freed sufficiently at the point of detection that
it is impossible to produce any meaningful dump of their contents. This
feature was implemented by the indefatigable Nicholas Clark, based on an idea
by Mike Giroux.

Platform Specific Problems

The optimiser on HP-UX 11.23 (Itanium 2) is currently partly disabled (scaled
down to +O1) when using HP C-ANSI-C; the cause of problems at higher
optimisation levels is still unclear.

There are a handful of remaining test failures on VMS, mostly due to
test fixes and minor module tweaks with too many dependencies to
integrate into this release from the development stream, where they have
all been corrected. The following is a list of expected failures with
the patch number of the fix where that is known:

ext/Devel/PPPort/t/ppphtest.t #26913

ext/List/Util/t/p_tainted.t #26912

lib/ExtUtils/t/PL_FILES.t #26813

lib/ExtUtils/t/basic.t #26813

t/io/fs.t

t/op/cmp.t

Reporting Bugs

If you find what you think is a bug, you might check the articles
recently posted to the comp.lang.perl.misc newsgroup and the perl
bug database at http://bugs.perl.org. There may also be
information at http://www.perl.org, the Perl Home Page.

If you believe you have an unreported bug, please run the perlbug
program included with your release. Be sure to trim your bug down
to a tiny but sufficient test case. Your bug report, along with the
output of perl -V
, will be sent off to perlbug@perl.org to be
analysed by the Perl porting team. You can browse and search
the Perl 5 bugs at http://bugs.perl.org/